1. Field of the Invention
The present invention relates to a power transmission device.
2. Description of the Related Art
Oil bath motors are structured such that a motor and a reducer are encapsulated in spaces communicating with each other and lubricant oil is circulated in the spaces. In an oil bath motor such as this, metal powder created as a result of sliding motion between components may be circulated along with the lubricant oil and supplied to the slide portions with the result that the slide portions may be unusually abraded.
One prior art discloses a compressor comprising: a power device composed of a stator and a rotor having a permanent magnet embedded therein; an airtight container for storing lubricant oil; and an oil feeding mechanism for pumping the lubricant oil stored in the airtight container so as to circulate the lubricant, wherein a through hole in which the lubricant flows is formed by drilling the rotor so as to be integrated with an air gap portion in which the permanent magnet is embedded. This allows iron powder mixed with the lubricant oil and circulated to be captured by the permanent magnet.